Pivot wider fails when the class of variable is a vector longer than one.

[jwilliman]

When running pivot_wider over data where one of the character variables is labelled using the Hmisc::label function, I get the warning message Error: Only bare vectors have shapes.

The Hmisc::label function not only adds a label attribute to the variable, but it changes the variable class to c("labelled", "character").

I found that I could reproduce this error by adding to the class of any variable prior to using pivot_wider. Interestingly, this doesn't occur for factors - so I'm guessing factor variables are treated differently?

I'm not sure if editing the class of a variable is peculiar to Hmisc (and should be corrected there), or whether it should be considered acceptable in general and thus catered for?

## This works
data("fish_encounters")
fish_encounters$fish <- as.character(fish_encounters$fish)
fish_encounters %>% pivot_wider(names_from = station, values_from = seen)

## So does this
data("fish_encounters")
class(fish_encounters$fish) <- c("factor", "extra")
fish_encounters %>% pivot_wider(names_from = station, values_from = seen)

## But these all fail
data("fish_encounters")
fish_encounters$fish <- as.character(fish_encounters$fish)
class(fish_encounters$fish) <- c("character", "extra")
fish_encounters %>% pivot_wider(names_from = station, values_from = seen)

data("fish_encounters")
fish_encounters$station<- as.character(fish_encounters$station)
class(fish_encounters$station) <- c("character", "extra")
fish_encounters %>% pivot_wider(names_from = station, values_from = seen)

data("fish_encounters")
class(fish_encounters$seen) <- c("integer", "extra")
fish_encounters %>% pivot_wider(names_from = station, values_from = seen)

[hadley]

Could you please rework your reproducible example to use the reprex package ? That makes it easier to see both the input and the output, formatted in such a way that I can easily re-run in a local session.

[jeffreypullin]

Minimal reprex:

x <- 1:10
Hmisc::label(x) <- "x's label"
vctrs:::shape(x)
#> Only bare vectors have shapes.

^{Created on 2019-10-19 by the reprex package (v0.3.0)}

So this is a duplicate of #773 and hence r-lib/vctrs#614.

[hadley]

Thanks for the investigation @jeffreypullin!